Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['Y', 'N', '6675', '7451', '5999', 'G']

25, 14, 6675, 7451, 5999, 7